The invention relates generally to an adjustable seating article such as a chair.
More particularly, the invention relates to a control mechanism for an adjustable seating article, especially an armchair or other chair for office use. Such a control mechanism may be employed to change the position of one or more adjustable components, e.g. the seat and/or the back rest, of the seating article.
A known type of adjustable seating article has an air spring or the like which is connected with an adjustable component of the seating article. Adjustment of the component is performed against the action of the spring. The spring has an engaged condition in which the resistance to adjustment is high and only a limited amount of adjustment is possible. The spring further has a disengaged condition in which the resistance to adjustment is low and adjustment over a wide range is possible. A handle or similar control element is provided to convert the spring between its engaged and disengaged conditions.
In one conventional form of control mechanism, the spring is brought into and maintained in its disengaged condition by applying a force to the handle. The seating article is adjusted as desired while the force continues to be applied to the handle. Once the desired adjustment has been achieved, the handle is released thereby bringing the spring into its engaged condition and locking the seating article in its adjusted position.
This control mechanism is inconvenient since it is difficult to perform adjustments while applying a force to the handle.
In another known form of control mechanism, a special locking element is provided to hold the handle in the position corresponding to the disengaged condition of the spring. A variation of this control mechanism has a handle which is pivotable between two positions respectively corresponding to the engaged and disengaged conditions of the spring. The handle is further mounted for sliding movement, e.g. in axial direction thereof, so as to enable the handle to be locked in the position where the spring assumes its disengaged condition.
While a control mechanism of the type in which the handle can be locked reduces the difficulty of adjustment, it is relatively inconvenient to operate. This is in large part due to the fact that, for the sake of appearance, the handle is located out of sight so that visual observation of the latter during operation is not possible.